Self centering of a drill may be achieved by utilizing a known principle: minimizing a tangent angle, near the chisel edge, formed between a tangent to a cutting edge and an axis of rotation of the drill. Many different approaches have been taken in order to achieve optimal drill point geometry. The design of the cutting edges in general and near the chisel edge in particular is usually a tradeoff between toughness of the drill point and the ability to penetrate the workpiece efficiently. Drills having a generally sharper drill point design will generally penetrate the workpiece more easily but in most cases that may be at the expense of a more fragile drill point. A more robust, wider design of the drill point will make it sturdier but it may be more difficult for the drill point to pierce the workpiece and center the drill. An important aspect, dependant of drill point and cutting edge geometry is the power required to operate the drilling machine, more specifically, the axial power required to overcome the axial stress on the drill while machining.